US5861826A
Expired / Lapsed
US
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Method and apparatus for calibrating integrated circuit analog-to-digital converters
Assignee: Intersil Americas LLC
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Filing: 1997-06-30
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Granted: 1999-01-19
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Expires: 2017-06-30
Abstract
Abstract The calibration method preferably comprises the steps of: driving the analog-to-digital converter (ADC) with at least one test signal; calibrating the driven ADC over a series of successive ADC calibrations; generating a series of successive ADC figure of merit measurements for respective successive ADC calibrations, the series of successive ADC figure of merit measurements defining at least a portion of a curve having a local minimum/maximum; and stopping calibrating at an ADC calibration corresponding to the local minimum/maximum of the curve defined by the series of successive ADC figure of merit measurements. The step of calibrating preferably comprises incrementally calibrating the ADC over the series of successive ADC calibrations. The method preferably further comprises the step of determining the local minimum/maximum of the curve. In particular, the step of determining preferably comprises fitting an equation to the series of ADC figure of merit measurements; and calculating the local minimum/maximum based upon the equation. Of course, the step of fitting the equation preferably comprises fitting the equation based upon a predetermined number of prior ADC figure of merit measurements. The step of fitting the equation may comprise fitting a polynomial equation, such as a third order equation, to the series of ADC figure of merit measurements. In addition, the step of calculating the local minimum/maximum may preferably comprise calculating a first derivative of the equation.
Inventors
- 👤 Tzi-Hsiung Shu
- 👤 George E. Von Dolteren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:28
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/10; H03M1/1009; H03M1/1033; H03M1/12; H03M1/66
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
96 words
A method for calibrating an analog-to-digital converter (ADC), the method comprising the steps of: driving the ADC with at least one test signal; calibrating the driven ADC over a series of successive ADC calibrations; generating a series of successive ADC figure of merit measurements for respective successive ADC calibrations, the series of successive ADC figure of merit measurements defining at least a portion of a curve having a local minimum/maximum; and stopping calibrating at an ADC calibration corresponding to the local minimum/maximum of the curve defined by the series of successive ADC figure of merit measurements.
Claim 2
Independent Claim
96 words
A method for calibrating an analog-to-digital converter (ADC), the method comprising the steps of: driving the ADC with at least one test signal; calibrating the driven ADC over a series of successive ADC calibrations; generating a series of successive ADC figure of merit measurements for respective successive ADC calibrations, the series of successive ADC figure of merit measurements defining at least a portion of a curve having a local minimum/maximum; and stopping calibrating at an ADC calibration corresponding to the local minimum/maximum of the curve defined by the series of successive ADC figure of merit measurements.
Claim 3
Dependent Claim
18 words
A method according to claim 1 further comprising the step of determining the local minimum/maximum of the curve.
Claim 4
Dependent Claim
39 words
A method according to claim 2 wherein the step of determining the local minimum/maximum comprises the steps of: fitting an equation to the series of ADC figure of merit measurements; and calculating the local minimum/maximum based upon the equation.
Claim 5
Dependent Claim
28 words
A method according to claim 3 wherein the step of fitting an equation comprises fitting same based upon a predetermined number of prior ADC figure of merit measurements.
Claim 6
Dependent Claim
31 words
A method according to claim 3 wherein the step of stopping the calibrating comprises stopping the calibrating based upon reaching the calculated local minimum/maximum to thereby avoid over calibrating the ADC.
Claim 7
Dependent Claim
30 words
A method according to claim 3 wherein the step of fitting the equation comprises the step of fitting a polynomial equation to the series of ADC figure of merit measurements.
Claim 8
Dependent Claim
31 words
A method according to claim 3 wherein the step of fitting the equation comprises the step of fitting a third order equation to the series of ADC figure of merit measurements.
Claim 9
Dependent Claim
25 words
A method according to claim 3 wherein the step of calculating the local minimum/maximum comprises the step of calculating a first derivative of the equation.
Claim 10
Dependent Claim
39 words
A method according to claim 1 wherein the step of generating the series of respective ADC figure of merit measurements comprises generating a series of figure of merit measurements which can tolerate a non-ideal at least one input signal.
Claim 11
Dependent Claim
68 words
A method according to claim 9 wherein the step of generating the series of respective ADC figure of merit measurements which can tolerate a non-ideal at least one input signal comprises generating a series of at least one of signal-to-noise ratio (SNR) measurements, signal-to-noise and distortion (SINAD) measurements, total harmonic distortion (THD) measurements, spurious free dynamic range (SFDR) measurements, integral nonlinearity (INL) measurements, and differential nonlinearity (DNL) measurements.
Claim 12
Dependent Claim
36 words
A method according to claim 1 further comprising the step of determining the at least one test input signal so that same causes a relatively large degradation in a predetermined figure of merit for the ADC.
Claim 13
Dependent Claim
25 words
A method according to claim 1 wherein the ADC includes a digital-to-analog converter (DAC), and further comprising the step of calibrating error from the DAC.
Claim 14
Dependent Claim
21 words
A method according to claim 1 wherein the step of calibrating comprises at least one of laser trimming and digital calibrating.
Claim 15
Dependent Claim
23 words
A method according to claim 1 wherein the step of calibrating comprises incrementally calibrating the ADC over the series of successive ADC calibrations.
Claim 16
Independent Claim
91 words
A method for calibrating an analog-to-digital converter (ADC), the method comprising the steps of: driving the ADC with at least one test signal; calibrating the driven ADC over a plurality of ADC calibrations; generating a plurality of ADC figure of merit measurements for respective ADC calibrations, the plurality of ADC figure of merit measurements defining at least a portion of a curve having a local minimum/maximum; and stopping calibrating at an ADC calibration corresponding to the local minimum/maximum of the curve defined by the plurality of ADC figure of merit measurements.
Claim 17
Independent Claim
91 words
A method for calibrating an analog-to-digital converter (ADC), the method comprising the steps of: driving the ADC with at least one test signal; calibrating the driven ADC over a plurality of ADC calibrations; generating a plurality of ADC figure of merit measurements for respective ADC calibrations, the plurality of ADC figure of merit measurements defining at least a portion of a curve having a local minimum/maximum; and stopping calibrating at an ADC calibration corresponding to the local minimum/maximum of the curve defined by the plurality of ADC figure of merit measurements.
Claim 18
Dependent Claim
18 words
A method according to claim 15 further comprising the step of determining the local minimum/maximum of the curve.
Claim 19
Dependent Claim
37 words
A method according to claim 16 wherein the step of determining the local minimum/maximum comprises the steps of: fitting an equation to the ADC figure of merit measurements; and calculating the local minimum/maximum based upon the equation.
Claim 20
Dependent Claim
28 words
A method according to claim 17 wherein the step of fitting an equation comprises fitting same based upon a predetermined number of prior ADC figure of merit measurements.
Claim 21
Dependent Claim
31 words
A method according to claim 17 wherein the step of stopping the calibrating comprises stopping the calibrating based upon reaching the calculated local minimum/maximum to thereby avoid over calibrating the ADC.
Claim 22
Dependent Claim
28 words
A method according to claim 17 wherein the step of fitting the equation comprises the step of fitting a polynomial equation to the ADC figure of merit measurements.
Claim 23
Dependent Claim
29 words
A method according to claim 17 wherein the step of fitting the equation comprises the step of fitting a third order equation to the ADC figure of merit measurements.
Claim 24
Dependent Claim
25 words
A method according to claim 17 wherein the step of calculating the local minimum/maximum comprises the step of calculating a first derivative of the equation.
Claim 25
Dependent Claim
34 words
A method according to claim 15 wherein the step of generating the respective ADC figure of merit measurements comprises generating figure of merit measurements which can tolerate a non-ideal at least one input signal.
Claim 26
Dependent Claim
63 words
A method according to claim 23 wherein the step of generating the respective ADC figure of merit measurements which can tolerate a non-ideal at least one input signal comprises generating at least one of signal-to-noise ratio (SNR) measurements, signal-to-noise and distortion (SINAD) measurements, total harmonic distortion (THD) measurements, spurious free dynamic range (SFDR) measurements, integral nonlinearity (INL) measurements, and differential nonlinearity (DNL) measurements.
Claim 27
Dependent Claim
36 words
A method according to claim 15 further comprising the step of determining the at least one test input signal so that same causes a relatively large degradation in a predetermined figure of merit for the ADC.
Claim 28
Dependent Claim
25 words
A method according to claim 15 wherein the ADC includes a digital-to-analog converter (DAC), and further comprising the step of calibrating error from the DAC.
Claim 29
Dependent Claim
21 words
A method according to claim 15 wherein the step of calibrating comprises at least one of laser trimming and digital calibrating.
Claim 30
Dependent Claim
16 words
A method according to claim 15 wherein the step of calibrating comprises incrementally calibrating the ADC.
Claim 31
Independent Claim
98 words
An apparatus for calibrating an analog-to-digital converter (ADC) comprising: drive means for driving the ADC with at least one test signal; calibrating means for calibrating the ADC over a plurality of ADC calibrations; measuring means for generating a plurality of ADC figure of merit measurements for respective ADC calibrations, the plurality of ADC figure of merit measurements defining at least a portion of a curve having a local minimum/maximum; and calibrating stop means for stopping calibrating at an ADC calibration corresponding to the local minimum/maximum of the curve defined by the plurality of ADC figure of merit measurements.
Claim 32
Independent Claim
98 words
An apparatus for calibrating an analog-to-digital converter (ADC) comprising: drive means for driving the ADC with at least one test signal; calibrating means for calibrating the ADC over a plurality of ADC calibrations; measuring means for generating a plurality of ADC figure of merit measurements for respective ADC calibrations, the plurality of ADC figure of merit measurements defining at least a portion of a curve having a local minimum/maximum; and calibrating stop means for stopping calibrating at an ADC calibration corresponding to the local minimum/maximum of the curve defined by the plurality of ADC figure of merit measurements.
Claim 33
Dependent Claim
22 words
An apparatus according to claim 29 wherein said calibrating stop means comprises determining means for determining the local minimum/maximum of the curve.
Claim 34
Dependent Claim
37 words
An apparatus according to claim 30 wherein the determining means comprises: equation fitting means for fitting an equation to the ADC figure of merit measurements; and calculating means for calculating the local minimum/maximum based upon the equation.
Claim 35
Dependent Claim
29 words
An apparatus according to claim 30 wherein the equation fitting means comprises means for fitting the equation based upon a predetermined number of prior ADC figure of merit measurements.
Claim 36
Dependent Claim
31 words
An apparatus according to claim 31 wherein the calibrating stop means comprises means for stopping the calibrating based upon reaching the calculated local minimum/maximum to thereby avoid over calibrating the ADC.
Claim 37
Dependent Claim
25 words
An apparatus according to claim 31 wherein the equation fitting means comprises means for fitting a polynomial equation to the ADC figure of merit measurements.
Claim 38
Dependent Claim
26 words
An apparatus according to claim 31 wherein the equation fitting means comprises means for fitting a third order equation to the ADC figure of merit measurements.
Claim 39
Dependent Claim
20 words
An apparatus according to claim 31 wherein the calculating means comprises means for calculating a first derivative of the equation.
Claim 40
Dependent Claim
29 words
An apparatus according to claim 29 wherein the measuring means comprises means for generating ADC figure of merit measurements which can tolerate a non-ideal at least one input signal.
Claim 41
Dependent Claim
52 words
An apparatus according to claim 37 wherein the measuring means comprises means for generating ADC figure of merit measurements from at least one of signal-to-noise ratio (SNR) measurements, signal-to-noise and distortion (SINAD) measurements, total harmonic distortion (THD) measurements, spurious free dynamic range measurements, integral nonlinearity (INL) measurements, and differential nonlinearity (DNL) measurements.
Claim 42
Dependent Claim
39 words
An apparatus according to claim 29 wherein said drive means further comprises means for determining the at least one test input signal so that same causes a relatively large degradation in a predetermined figure of merit for the ADC.
Claim 43
Dependent Claim
26 words
An apparatus according to claim 29 wherein the ADC includes a digital-to-analog converter (DAC), and further comprising DAC calibrating means for calibrating error from the DAC.
Claim 44
Dependent Claim
22 words
An apparatus according to claim 29 wherein the calibrating means comprises means for at least one of laser trimming and digital calibrating.
Claim 45
Dependent Claim
17 words
An apparatus according to claim 29 wherein the calibrating means comprises means for incrementally calibrating the ADC.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-01-18 | 2002-07-20 | 2003-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-01-18 | 2006-07-20 | 2007-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-01-18 | 2010-07-20 | 2011-01-19 | $7700.00 | Window Closed / Lapsed |